Kittycat...
Did you use the same product that you would use on house plants?
Or something that looked more like large chunks of bark?
Most orchids grow ON trees with their roots exposed to air and rain, putting them in a pot and getting them to grow is challenging enough. But it's CRITICAL that you use a mix that drains and dries rapidly. Both Lowe's and HomeDepot sell a mix made by 'Better-Gro' specifically for Orchids. In fact, they have several blends. My experience with Miracle Grow products is that they are too fine, and won't drain as quickly as your orchids need.
Good luck with your plant , let us know how it works out.
